The basic elements of the gold based alloy of the present invention, primarily gold, copper, zinc and silver are well known and frequently used in the jewelry industry. This invention uses these elements (other than the gold component for standard karat contents, 10-18K) in amounts and ratios believed undisclosed in the art to create a gold alloy with an entirely new color and character. In examination of the known prior art, what is found reveals no attempts to create a gold jewelry alloy of a very unusual, and separate color, having an improved aesthetic relationship between typical skin tones and jewelry related materials such as gemstones.
Prior work has mainly shown improvements on existing "standard" colors as it would relate to specific metallurgic properties, or the maintenance of standard colored alloys while lowering or altering gold content for an economic advantage.
Other prior art alloys have disclosed ideas that relate to very broad ranges of gold content, but formulate very small amounts of a variety of elements that perhaps create a characteristic (reversible hardness, a spring effect, or deoxidant, etc.) that is generally applicable only to a very small segment of jewelry manufacturing. This invention targets a specific karat span, and a relatively small variable range for the acceptable formula.
Standard colors of gold known to the manufacturing of jewelry are yellow, white, green and rose or pink and are generally alloyed to form a 10 karat to 18 karat gold product. The jewelry industry as a whole is believed lacking an alloy of any kind that has a complimenting color to the skin tones it is typically worn against. From an aesthetic point of view, the problems prior art metals have had are the yellows were very cool tones, while the pink or rose alloys were very warm tones, offering only metals of high contrast to most skin tones. The present invention addresses this problem with an alloy that is very much a mid-tone in terms of color and "temperature" but still maintains the important metallurgic characteristics of known quality karat golds, e.g., high degree of lustre and shine, tarnish and corrosion resistance, resistance to cracking, surface smoothness and very good wear and durability properties.
Other requirements for an alloy to be practically utilized in the jewelry industry are that it can readily be cast, soldered or cold worked, such as forging and rolling. Preferable metallurgic and physical properties for a gold jewelry alloy include a moderate level of hardness to extend the jewelry pieces wear and polish life without adversely affecting malleability and ductility. Hardness is also a concern in the area of surface finishing jewelry, i.e., sawing, shearing, filing, tumbling, sanding, and polishing. A high level of malleability and ductility becomes important to an alloy when the manufacturing process includes forging and/or machine forming, or is required to be made into various forms of sheet and wire. A jewelry alloy should also have a level of fluidity that allows smooth, detailed castings. The goods made from the alloy, whether cast or formed should be easily joinable with solders. An ideal alloy would have these properties as well as having excellent memory (ability to hold form) and annealability (a resoftening process using heat).